Level: Upper Intermediate to Advanced
Materials: Slips of paper with one noun written on each (at least 20), a bag, hat or other container

Divide the class into teams of three or four. One member from one team stands up and draws a noun from the bag. The student's job is to make one sentence about the noun with an adjective clause so that his or her team can guess the noun. Ex:

HORSE
This is an animal that is used in racing.

CAR
This is something which I drive to school.

The team gets one guess. If the team fails, the student can make one more sentence, and any team can guess. Correct answers earn points, and play passes to the next team. For variety, you can impose time limits, deduct points for wrong pronoun use (that, which, etc.), or add forbidden words to the slips of paper.